Problem with converting touch position to world space

Hello, I wanted to convert touch position to a world space point and then rotate a RigidBody towards it, I can't nail down why doesn't it work, I would appreciate your help greatly.

 void Update () 
 {
     if(Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Began)
     {
         Ray ray = Camera.main.ScreenPointToRay(Input.GetTouch(0).position);
         Plane plane = new Plane(Vector3.up, transform.position);
         float distance = 0; 
         if (plane.Raycast(ray, out distance)){ 
             Vector3 pos = ray.GetPoint(distance);
             float rotZ = Mathf.Atan2 (pos.y, pos.x) * Mathf.Rad2Deg;
             myBody.rotation = Quaternion.Euler (0f, 0f, rotZ + 90);
       
         }
     }
 }